"Trump is a chump," Hill tweeted on 8 December last year. It was a response to Scottish Conservative leader, Ruth Davidson, who unleashed a list of insults against Trump inspired by her homeland.

Twitter

Hill was not alone in expressing strident views about Trump. Her colleague Timothy has tweeted about the US president a number of times — and nearly always in a negative light.

As Politico has reported, Timothy balked at the prospect of building bridges with Trump back in May. "Urgh," he wrote, "as a Tory I don't wand any 'reaching out' to Trump." He also criticised television presenter Piers Morgan for being "obsequious" about the US president. In another tweet, Timothy said:

Twitter Hill and Timothy were appointed joint chiefs of staff soon after May entered 10 Downing Street in July. A profile on the pair in the Evening Standard described them as "two fiercely loyal chiefs of staff who hold the key to her success."

May emphasised the importance of the partnership between the US and Britain in a phone call with Trump on Thursday. "She highlighted her wish to strengthen bilateral trade and investment with the US as we leave the EU," 10 Downing Street said in a statement.